1. Field of the Invention
The present invention relates to a video game apparatus for playing an action video game such as a combat video game or a competitive video game such as a sports game in video game images displayed on a display screen which include game characters (competitive characters) movable in a pseudo-three-dimensional space containing object models of a pillar, a container, etc. as obstacles, a method of processing video game images in such a video game, and a computer-readable recording medium which stores a game program of such a video game.
2. Description of the Prior Art
Some video game apparatus display video game images on a display screen which represent a pseudo-three-dimensional space containing object models of pillars, obstacles, etc. When a combat video game, for example, is played on such a video game apparatus, a player character controlled by the game player and an opponent character controlled by the controller, including a CPU (Central Processing Unit), of the video game apparatus are displayed in the pseudo-three-dimensional space. In the displayed pseudo-three-dimensional space, the player character which moves in response to commands manually entered by the game player fights with the opponent character which is automatically moved by the controller according to a predetermined control program and control data. The game player controls the player character in an attempt to deliver an attacking action such as a kick or a punch from the player character to the opponent character in order to cause damage to the opponent character.
If the damage to the opponent character cannot be reduced below a certain level upon elapse of a predetermined time or the player character suffers damage beyond a certain level due to attacking actions such as kicks or punches from the opponent character, then the combat video game is over.
One problem with conventional combat video games is that when the viewpoint of a hypothetical camera is located at a certain position in the field of the pseudo-three-dimensional space, an object model such as a pillar in the field comes in front of the viewpoint of the hypothetical camera, concealing on the display screen important battle information of a game character which represents whether the game character is squatting or jumping.
According to a proposed solution, when the opponent character, for example, is positioned behind an object model such as a pillar, the object model is switched from an opaque rendition to a translucent rendition in its entirety, allowing the game player to see the opponent character through the translucent object model that overlaps the opponent character.
Since the object model changes from the opaque presentation to the translucent presentation when the opponent character is brought behind the object model, the game player is able to acquire desired information of the opponent character behind the object model. However, the game player who is viewing the displayed image feels somewhat strange and unnatural because the object model suddenly changes itself to the translucent appearance.
It is therefore an object of the present invention to provide a video game apparatus which is capable of allowing a game player to naturally acquire visual information of a game character positioned behind a displayed object model in a video game without causing the game player to feel strange and unnatural.
Another object of the present invention is to provide a method of processing video game images in such a video game.
Still another object of the present invention is to provide a computer-readable recording medium which stores a game program of such a video game.
According to the present invention, there is provided a video game apparatus for playing a video game in a game image displayed on a display screen and including a game character movable in a pseudo-three-dimensional space containing an object model. The video game apparatus has translucent information storage means for storing transparency levels of pixels of an object model which correspond to distances from the viewpoint of a hypothetical camera which is capturing an image of a game character, to the respective pixels of the object model, the transparency levels being higher as the distances are smaller, and transparency control means for determining distances from the viewpoint of the hypothetical camera to pixels of an object model as an obstacle behind which the game character is concealed as viewed from the viewpoint of the hypothetical camera, determining transparency levels corresponding to the determined distances, respectively, from the translucent information storage means, generating image data of the pixels of the object model as the obstacle based on the determined transparency levels, and combining the generated image data with image data of the game character.
Alternatively, in the above video game apparatus, the transparency control means may determine distances from the viewpoint of the hypothetical camera to pixels of an object model positioned forward of the game character as viewed from the viewpoint of the hypothetical camera, determine transparency levels corresponding to the determined distances, respectively, from the translucent information storage means, generate image data of the pixels of the object model based on the determined transparency levels, and combine the generated image data with image data of the game character.
Further alternatively, in the above video game apparatus, the transparency control means may determine distances from the viewpoint of the hypothetical camera to pixels of an object model if the object model is positioned closer than the game character to the viewpoint of the hypothetical camera, determine transparency levels corresponding to the determined distances, respectively, from the translucent information storage means, generate image data of the pixels of the object model as the obstacle based on the determined transparency levels, combine the generated image data with image data of the game character, and fog a color of the object model if the object model is positioned farther than the game character from the viewpoint of the hypothetical camera.
According to the present invention, there is also provided a method of processing a game image displayed on a display screen and including a game character movable in a pseudo-three-dimensional space containing an object model. The method comprises the steps of determining distances from the viewpoint of a hypothetical camera which is capturing an image of a game character to pixels of an object model as an obstade behind which the game character is concealed as viewed from the viewpoint of the hypothetical camera, determining transparency levels corresponding to the determined distances, respectively, from a transparency information table, the transparency levels being higher as the distances are smaller, generating image data of the pixels of the object model based on the determined transparency levels, and combining the generated image data with image data of the game character.
Alternatively, in the above method, distances from the viewpoint of a hypothetical camera which is capturing an image of a game character to pixels of an object model positioned forward of the game character as viewed from the viewpoint of the hypothetical camera may be determined.
Further alternatively, in the above method, distances from the viewpoint of a hypothetical camera which is capturing an image of a game character to pixels of an object model may be determined if the object model is positioned closer than the game character to the viewpoint of the hypothetical camera, and a color of the object model may be fogged if the object model is positioned farther than the game character from the viewpoint of the hypothetical camera.
According to the present invention, there is also provided a computer-readable recording medium storing a control program for playing a video game in a game image displayed on a display screen and including a game character movable in a pseudo-three-dimensional space containing an object model. The control program comprises the steps of identifying an object model as an obstacle behind which a game character is concealed as viewed from the viewpoint of a hypothetical camera which is capturing an image of the game character, determining distances from the viewpoint of the hypothetical camera pixels of the object model, determining transparency levels corresponding to the determined distances, respectively, from a transparency information table, the transparency levels being higher as the distances are smaller, generating image data of the pixels of the object model based on the determined transparency levels, and combining the generated image data with image data of the game character.
Alternatively, in the above control program, an object model positioned forward of a game character as viewed from the viewpoint of a hypothetical camera which is capturing an image of the game character may be identified.
Further alternatively, in the above control program, distances from the viewpoint of a hypothetical camera which is capturing an image of a game character to pixels of an object model may be determined if the object model is positioned closer than the game character to the viewpoint of the hypothetical camera, and a color of the object model may be fogged if the object model is positioned farther than the game character from the viewpoint of the hypothetical camera.
The above and other objects, features, and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.